In some areas of medicine, there is trend towards lower volume, higher concentration dosages of therapeutic compounds and drugs to be delivered via injection, typically by syringe. For example, in the cosmetic surgery field, recent trends include procedures termed “High Dose Micro-focused” or “HDMF” injections of botulinum toxin, which may involve the use of high concentration and relatively small delivered volumes of compounds or mixtures compared to the concentrations and volumes that have, in the past, been typically used for such injections in cosmetic treatments and in very precise amounts and in very focused, localized areas of the human face and body. The cost of these compounds and mixtures are relatively high to begin with. As the concentrations increase, the relative cost of wasted amounts of the compounds and mixtures also increases.
A number of problems in the prior art stem from the limitations of existing syringes to be adapted to precision, low dose/volume applications. For example, the ability to deliver precise volumes in increments of as small as 0.01 ml may typically be required in such applications. Existing syringe configurations are not readily adapted to precise control of delivery such small increments. A related problem is accurate control and reading of syringes as the form factor becomes reduced. Still another problem is that prior art syringe configurations may demonstrate structural deficiencies when their form factor is reduced. More specifically, for example, reducing the plunger diameter significantly to fit within a reduced syringe lumen may render the plunger susceptible to buckling or bending when a force is applied, thus affecting syringe function and accuracy. Ergonomic factors, including user comfort and control and readability of syringe indicia and plunger position also become a factor as the lumen diameter and other parameters are reduced.
Yet another problem is the need to reduce wasted residual amounts left undelivered in the “dead space” of prior art syringes, as the concentration of expensive substances, such as botulinum toxin in a delivery medium (solvent) increases, the cost of wasted amounts of the mixture also increases. Another problem relates to the structural shortcomings of traditional syringes when their form factor is reduced in size.
Yet another problem is the need for precise control of the dispensing of syringe contents, such as dermal fillers and other compositions that may be of a relatively high viscosity.
It would therefore be advantageous to provide devices, including syringes and attachments that address the aforementioned shortcoming and others in the prior art.